The are a group of
volcanic
A volcano is a rupture in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface.
On Earth, volcanoes are most often found where tectonic plat ...
islands stretching south and east from the
Izu Peninsula of
Honshū, Japan. Administratively, they form two towns and six villages; all part of
Tokyo Prefecture
Tokyo (; ja, 東京, , ), officially the Tokyo Metropolis ( ja, 東京都, label=none, ), is the capital and largest city of Japan. Formerly known as Edo, its metropolitan area () is the most populous in the world, with an estimated 37.468 ...
. The largest is
Izu Ōshima, usually called simply Ōshima.
Although usually called the "
Seven Islands of Izu" (
伊豆七島 in Japanese), there are in fact more than a dozen islands and islets. Nine among them are currently inhabited.
Geography
The Izu islands stretch south-east from the
Izu Peninsula on
Honshu
, historically called , is the largest and most populous island of Japan. It is located south of Hokkaidō across the Tsugaru Strait, north of Shikoku across the Inland Sea, and northeast of Kyūshū across the Kanmon Straits. The island s ...
and cover an area of approximately . There are nine populated islands with a total population of 24,645 people () spread over . The largest of them is Izu Oshima (8,346 inhabitants, ), the smallest Toshima (292 inhabitants, .) Of the inhabited islands, seven are traditionally referred to as the "Izu Seven": Oshima, Toshima, Niijima, Kozujima, Miyakejima, Hachijojima, and Mikurajima, though Shikinejima and Aogashima are sometimes included as well.
Each of the islands has its unique character: Oshima is noted for its active
volcano
A volcano is a rupture in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface.
On Earth, volcanoes are most often found where tectonic plates ...
Mt Mihara and
camellia
''Camellia'' (pronounced or ) is a genus of flowering plants in the family Theaceae. They are found in eastern and southern Asia, from the Himalayas east to Japan and Indonesia. There are more than 220 described species, with some controve ...
s, Hachijojima for its former penal colony, Mikurajima for dolphin watching, Niijima for its numerous beaches, Kozujima for its white sandy shores, Hachijojima for its well-preserved unique culture, and Miyakejima for the 2001 volcanic eruption.
During the
Edo period
The or is the period between 1603 and 1867 in the history of Japan, when Japan was under the rule of the Tokugawa shogunate and the country's 300 regional '' daimyo''. Emerging from the chaos of the Sengoku period, the Edo period was character ...
, Nii-jima, Miyake-jima, and Hachijō-jima served as places of exile for criminals.
The subtropical
Ogasawara Islands
The Bonin Islands, also known as the , are an archipelago of over 30 subtropical and tropical islands, some directly south of Tokyo, Japan and northwest of Guam. The name "Bonin Islands" comes from the Japanese word ''bunin'' (an archaic read ...
, which are also administratively part of Tokyo, lie further to the south. They form a far-flung archipelago of over thirty (30) islands some due south of Tokyo.
Islands
Administrative divisions
The Izu Islands are divided into two towns (Oshima and Hachijojima) and six villages (remaining inhabited islands.) Three
subprefectures are formed above the municipalities as branch offices of the
metropolitan government.
All the islands (more than a dozen in total) lie within the
Fuji-Hakone-Izu National Park. The four southernmost islands are not administrated under any town or village in Hachijō Subprefecture, but are
unincorporated area
An unincorporated area is a region that is not governed by a local municipal corporation. Widespread unincorporated communities and areas are a distinguishing feature of the United States and Canada. Most other countries of the world either hav ...
s.
Torishima is now uninhabited but is an important bird refuge.
Deserted islands between Aogashima and Ogasawara Islands, namely Bayonaise Rocks (''Beyonēzu Retsugan''),
Smith Island (''Sumisu-tō''),
Torishima, and
Lot's Wife (''Sōfu-iwa'') do not belong to any
municipality
A municipality is usually a single administrative division having corporate status and powers of self-government or jurisdiction as granted by national and regional laws to which it is subordinate.
The term ''municipality'' may also mean the ...
, because both Hachijō Town and Aogashima Village claim administrative rights. They are directly controlled by
Hachijō Subprefecture instead.
*
Ōshima Subprefecture
**
Ōshima Town:
Izu Ōshima
**
Toshima
is a special ward in Tokyo, Japan. It is one of the eight central wards of the Tokyo Metropolitan area. Located in the northern area of Tokyo, Toshima is bordered by the wards of Nerima, Itabashi, and Kita in the north and Nakano, Shinjuku, ...
Village:
Toshima
is a special ward in Tokyo, Japan. It is one of the eight central wards of the Tokyo Metropolitan area. Located in the northern area of Tokyo, Toshima is bordered by the wards of Nerima, Itabashi, and Kita in the north and Nakano, Shinjuku, ...
**
Niijima
is a volcanic Japanese island administered by the Tokyo Metropolitan Government. It is one of the Izu Seven Islands group of the seven northern islands of the Izu archipelago, and is located approximately south of Tōkyō and south of S ...
Village:
Niijima
is a volcanic Japanese island administered by the Tokyo Metropolitan Government. It is one of the Izu Seven Islands group of the seven northern islands of the Izu archipelago, and is located approximately south of Tōkyō and south of S ...
,
Shikinejima
is a volcanic Japanese island in the Philippine Sea. Nussbaum, Louis-Frédéric. (2005)"''Izu Shotō'',"''Japan Encyclopedia,'' p. 412. The island is administered by Tōkyō and located approximately south of Tōkyō and south of Shimoda Shi ...
, and
Udoneshima
**
Kōzushima Village:
Kōzushima
*
Miyake Subprefecture
is a subprefecture of Tokyo Metropolis, Japan. The organization belongs to the Tokyo Metropolitan Government Bureau Of General Affairs.
It includes the following villages on the Izu Islands:
* Miyake (village on Miyakejima
is an inhab ...
**
Miyake Village:
Miyakejima
is an inhabited volcanic island in the Izu archipelago in the Philippine Sea approximately southeast of Tokyo, Japan. As with the other islands in the Izu Island group, Miyake-jima forms part of the Fuji-Hakone-Izu National Park.
Etymo ...
and
Ōnoharajima
**
Mikurajima Village:
Mikurajima,
Inambajima
is a volcanic, deserted island located in the Philippine Sea approximately south of Tokyo and southwest of Mikura-jima, in the center of the Izu archipelago, Japan.
Geography
The island is an andesite pillar with sheer sides, the only visi ...
*
Hachijō Subprefecture
**
Hachijō Town:
Hachijōjima and
Hachijōkojima
**
Aogashima
is a volcanic island to the south of Japan in northernmost Micronesia. It is the southernmost and most isolated inhabited island of the Izus, which are politically and administratively part of Japan but geographically not part of the Japanese ...
Village:
Aogashima
is a volcanic island to the south of Japan in northernmost Micronesia. It is the southernmost and most isolated inhabited island of the Izus, which are politically and administratively part of Japan but geographically not part of the Japanese ...
**
unincorporated:
Bayonnaise Rocks (''Beyonēzu Retsugan''),
Sumisu-tō,
Torishima, and
Sōfu-iwa
Demographics
Though the population on the Izu Islands has been dropping, the phase is less dramatic than on other isolated Japanese islands.
The divergent
Hachijō language is spoken on the islands.
Infrastructure
The primary industries are fisheries, agriculture, and tourism. The most scenic spots on the islands are crowded with tourists during summers. Popular tourist activities include swimming, scuba diving, surfing, fishing, bird watching and trekking.
Transportation between the islands, by
cargo-passengers boats,
jetfoils, and
aircraft
An aircraft is a vehicle that is able to flight, fly by gaining support from the Atmosphere of Earth, air. It counters the force of gravity by using either Buoyancy, static lift or by using the Lift (force), dynamic lift of an airfoil, or in ...
, is supported by harbours on all inhabited islands and five airports (small islands can be reached by helicopter).
There are 5 airports, 15 harbors, and 19 fishing ports. Flights from Tokyo take 30 minutes, while boats take 7–10 hours and jetfoils make the route in about two hours. Transportation on the islands is considered important to the quality of life, which is why about of paved main roads have been constructed to serve various kinds of vehicles.
There was no electricity on the islands before 1953, but by 1962 98% of the area was receiving electricity.
Geology
The islands occupy the northern portion of the
Izu–Bonin–Mariana Arc which extends to the
Izu Peninsula and
Mount Fuji
, or Fugaku, located on the island of Honshū, is the highest mountain in Japan, with a summit elevation of . It is the second-highest volcano located on an island in Asia (after Mount Kerinci on the island of Sumatra), and seventh-highest ...
on the
Honshū mainland which are northern extensions of the Izu
volcanic arc. The Izu arc ends there at a tectonic
triple junction
A triple junction is the point where the boundaries of three tectonic plates meet. At the triple junction each of the three boundaries will be one of three types – a ridge (R), trench (T) or transform fault (F) – and triple junctions can b ...
.
Volcanic activity is frequent in the area. 31 people were killed when the research vessel ''Kaiyō Maru no 5'' was destroyed during the 1953 eruption of
Myōjin-shō. Volcanic activity, including the release of harmful gases, forced the evacuation of Miyake-jima in 2000. Residents were allowed to return permanently to the island in February 2005 but were required to carry
gas masks in case of future volcanic emissions.
To handle the various types of natural disasters threatening the region, including tsunamis, storm, floods, and volcanism, Tokyo metropolitan government has developed prevention and safety measures, including hazard maps and evacuation guidance, radios, signs, and a transport system for emergency supplies.
Ecology
A chain of volcanic islands, the Izu Archipelago are
oceanic islands that formed relatively recently (within a few million years) without any previous connection to mainland Japan. In contrast to isolated Pacific islands, such as
Hawaii
Hawaii ( ; haw, Hawaii or ) is a state in the Western United States, located in the Pacific Ocean about from the U.S. mainland. It is the only U.S. state outside North America, the only state that is an archipelago, and the only stat ...
and the
Galápagos, the Izu Islands are located near the mainland and have thus been frequently colonized by various species by overseas dispersal from the mainland or from adjacent islands. This make them interesting for the studies of
ecological and
evolution
Evolution is change in the heritable characteristics of biological populations over successive generations. These characteristics are the expressions of genes, which are passed on from parent to offspring during reproduction. Variation ...
ary processes.
''
Campanula'' (Bellflower) colonized the entire archipelago in a single event. Similarly, the ''
Euhadra
''Euhadra'' is a genus of air-breathing land snails, terrestrial pulmonate gastropod mollusks in the subfamily Bradybaeninae of the family Camaenidae. MolluscaBase eds. (2021). MolluscaBase. Euhadra Pilsbry, 1890. Accessed through: World R ...
'' snails, endemic to Japan, populated the islands in a single event and all individuals on inhabited islands possess an identical
haplotype
A haplotype ( haploid genotype) is a group of alleles in an organism that are inherited together from a single parent.
Many organisms contain genetic material ( DNA) which is inherited from two parents. Normally these organisms have their DNA o ...
. The ''
Apodemus'' mice, on the other hand, colonized the islands from the mainland in two independent events.
History
* 680 -
Izu Province was established in the form of being separated from
Suruga Province
was an old province in the area that is today the central part of Shizuoka Prefecture. Suruga bordered on Izu, Kai, Sagami, Shinano, and Tōtōmi provinces; and was bordered by the Pacific Ocean through Suruga Bay to the south. Its abbrev ...
. At that time, the Izu islands belonged to
Kamo-gun.
* 1643 - Explorer
Maarten Gerritsz Vries called it the ''De Vries Archipelago''
* November 14, 1871 (December 25, 1871) --- Due to the first prefectural integration, it became under the jurisdiction of Ashigara Prefecture.
* 1876 (Meiji 9), April 18 - Due to the second prefectural integration, it became under the jurisdiction of
Shizuoka Prefecture
is a prefecture of Japan located in the Chūbu region of Honshu. Shizuoka Prefecture has a population of 3,637,998 and has a geographic area of . Shizuoka Prefecture borders Kanagawa Prefecture to the east, Yamanashi Prefecture to the northea ...
.
* 1878 (Meiji 11), January 11 - will be under the jurisdiction of
Tokyo Prefecture
Tokyo (; ja, 東京, , ), officially the Tokyo Metropolis ( ja, 東京都, label=none, ), is the capital and largest city of Japan. Formerly known as Edo, its metropolitan area () is the most populous in the world, with an estimated 37.468 ...
See also
*
List of islands of Japan
References
* ''Teikoku's Complete Atlas of Japan'', Teikoku-Shoin Co., Ltd. Tokyo 1990,
* The official tokyo island information page
{{Authority control
*
Tourist attractions in Tokyo
Archipelagoes of Japan
Islands of Tokyo
Archipelagoes of the Pacific Ocean